Polyamine Groups Research Articles

Synthesis of novel 1:2 Fe-complexed dye containing polyamine groups

A Fe-complexed dye containing crosslinkable polyamine groups was synthesized through diazotization and coupling reaction, chlorination, amination and metallization. The structure of the Fe-complexed crosslinking dye was characterized by FT-IR and Atomic Absorption Spectroscopic techniques. The dyeing and light fastness properties of the Fe-complex on silk and wool were tested, and the results showed that the novel Fe-complex exhibited both high fixation and good light fastness.

Colorimetric sensing of pyrophosphate in aqueous media using bis-functionalised silica surfaces

Bis-functionalised silica surfaces have been designed in order to develop selective and sensitive probes for the chromo-fluorogenic detection of certain guests. The designed system consists of a siliceous support bis-functinalised with thiol and polyamine groups. Thiol groups are suitable reactive centres (R) that are know to react with squaraine dyes (D) inducing bleaching, whereas polyamines act as host sites (H) able to coordinate certain target guests (G). In the absence of G, the reactive groups (R) react with the dye resulting in a bleaching of the solution. On the contrary, the presence of certain guest (G) results in a control of the reaction kinetic between R and D and eventually in a complete reaction inhibition. Different functionalised solids were prepared by reaction of the siliceous surface with different concentrations of mercaptopropyltrimethoxysilane (MPTS) and 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (N3TS). The final materials (solids to ) were characterized employing standard procedures. In a first step the reactivity of the signaling dye D (squaraine ) with the reactive centre R (thiol groups) was studied as a function of the pH using solid that showed a most suitable response. At pH 7 and pH 5 there was a quick reaction between the squaraine and the thiol groups on the surface. On the contrary this reaction is significantly slower at pH 3 due to the different degree of protonation of the amines as a function of the pH. Additionally the reaction of with the squaraine has been studied in the presence of a range of inorganic anions with different structural dimensions and charges, including chloride, perchlorate, nitrate, sulfate, phosphate and pyrophosphate. At pH 3 the reaction of the dye with the thiol groups is still effective in the presence of chloride and perchlorate, but the reaction is highly inhibited in the presence of the anions nitrate, sulfate, phosphate and pyrophosphate. At pH 7 the squaraine reacts very fast with the thiol groups in the presence of all the anions studied. In contrast, at pH 5 only pyrophosphate is able to inhibit, to a certain extent, the reaction of the squaraine with the thiols, resulting in a selective chromo-fluorogenic detection of this anion in pure water. Finally, the observed behaviour was discussed in terms of both, the kinetic rates of the reaction between the thiol and the squaraine groups and the thermodynamic interaction reaction between the anions and the polyamine moieties.

Comparison of chelating ion exchange resins in sorption of copper(II) and zinc(II) complexes with ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA)

This paper investigates the macroporous chelating ion exchangers with different functional groups for their sorption properties towards the copper(II) and zinc(II) ions. The investigations by the dynamic and static methods were carried out in the presence of traditional complexing agents. The differences in affinity of Cu(II) and Zn(II) complexes with these complexones result from the kind of functional groups of the chelating ion exchangers, such as thiourea, aminomethylphosphonate, iminodiacetate, and polyamine groups as well as from the pH value. The quantitative removal of studied heavy metal complexes using chelating ion exchangers is achieved in the case when resins compete successfully for the heavy metal ions against these chelators.Key words: chelating resins, heavy metals, EDTA, NTA.

Application of a New-Generation Complexing Agent in Removal of Heavy Metal Ions from Aqueous Solutions

The paper presents the studies on removal of copper(II) and zinc(II) ions from aqueous solutions in the presence of the tetrasodium salt of polyaspartic acid carried out on commercially available, chelating ion exchangers with different functional groups which are widely applied in the recovery of heavy metal ions from industrial effluents. The research results indicate a high affinity of these resins for the zinc(II) and copper(II) ions. The sorption characteristics of each metal ion in the presence of the complexing agent onto the studied chelating ion exchangers with thiourea, aminomethylphosphonate, iminodiacetate, and polyamine groups were represented by the Langmuir isotherms quite well.

The effect of the controlled release of basic fibroblast growth factor from ionic gelatin-based hydrogels on angiogenesis in a murine critical limb ischemic model

The localized delivery of exogenous, angiogenic growth factors has become a promising alternative treatment of peripheral artery disease (PAD) and critical limb ischemia. In the present study, we describe the development of a novel controlled release vehicle to promote angiogenesis in a murine critical limb ischemic model. Ionic, gelatin-based hydrogels were prepared by the carbodiimide-mediated amidation reaction between the carboxyl groups of gelatin or poly- l-glutamic acid molecules and the amine groups of poly- l-lysine or gelatin molecules, respectively. The degree of swelling of the synthesized hydrogels was assessed as a function of EDC/NHS ratios and the pH of the equilibrating medium, while the release kinetic profile of basic fibroblast growth factor (FGF-2) was evaluated in human fibroblast cultures. The degree of swelling (DS) decreased from 26.5±1.7 to 18.5±2.4 as the EDC concentration varied from 0.75 to 2.5 mg/ml. Eighty percent of the FGF-2 was released at controlled rates from gelatin–polylysine (gelatin–PLL) and gelatin–polyglutamic acid (gelatin–PLG) hydrogel scaffolds over a period of 28 days. Cell adhesion studies revealed that the negatively charged surface of the gelatin–PLG hydrogels exhibited superior adhesion capabilities in comparison to gelatin–PLL and control gelatin surfaces. Laser Doppler perfusion imaging as well as CD31+ capillary immunostaining demonstrated that the controlled release of FGF-2 from ionic gelatin-based hydrogels is superior in promoting angiogenesis in comparison to the bolus administration of the growth factor. Over 4 weeks, FGF-2 releasing gelatin–PLG hydrogels exhibited marked reperfusion with a Doppler ratio of 0.889 (±0.04) which was 69.3% higher than in the control groups.

Studies of the Selective Removal of Micro-Quantities of Platinum(IV) Ions from Macro-Quantities of Model Solutions of Aluminium, Copper, Iron, Nickel and Zinc Chloride on Anion-Exchangers of Various Types

Platinum has been widely applied as an industrial catalyst and consequently the recovery of noble metals from industrial wastes has become an economic issue. In the present studies, laboratory tests were undertaken to examine the selective removal of micro-quantities of platinum(IV) from 1 M solutions of aluminium, copper, iron, nickel and zinc chloride in 0.1 M hydrochloric acid using anion-exchangers containing tertiary amine group functions (Amberlite IRA-67 and Amberlite IRA-93) and polyamine group functions (Diaion CR-20).The values of the recovery factor [% R Pt(IV)] were determined for these anion-exchangers, as well as the sorption isotherms whose shape and type depended on the kind of aqueous phase employed and the phase contact time. In addition, the weight and volume distribution coefficients as well as the working and total ion-exchange capacities were calculated from the Pt(IV) breakthrough curves and various kinetic parameters were determined.The anion-exchanger Amberlite IRA-93 exhibited a ...

Effect of ME-3451-106, an aqueous extract of Stichaster striatus with inhibitory activity of voluntary alcohol intake, in genetically drinker rats: Isolation and identification of the active fraction

The aqueous extract obtained from Stichaster striatus Müller & Troschel (Asteroidea, Stichasteridae) has been shown to possess activity as an alcohol appetite inhibitor after oral administration in a rat model with a genetically established excessive appetite for alcohol (Wistar rats, lineage UChB). A significant decrease in the consumption of ethanol was observed (unrelated to a possible disulfiram effect) without a change in the normal food or water intake during the experimentation period. A bio-guided fractionation of the extract was carried out in order to identify the most active fraction, in which the presence of a group of natural endogenous polyamines in undetermined proportions is suspected. Our hypothesis was to relate the activity obtained for the original ME-3451-106 extract with the presence of these polyamines in the extract in question. The activity shown by a series of commercially available polyamines (putrescine (Pu), spermidine (SPD) and spermine (SP)) in inhibiting voluntary ethanol intake lends support to our hypothesis. The extract was selected on the basis of oral tradition, which claimed that the consumption of a “soup” obtained by boiling starfish, later identified as Stichaster striatus, prevented the appearance of alcoholism in laborers on properties entrusted to the Jesuit order during the middle period of the Spanish conquest of America (17–18th century).

Competition of natural polyamines with dimethylsilyl analogues and monovalent cations in presence of a charged dipalmitoylphosphatidylglycerol monolayer

The interaction at the air/water interface of dipalmitoylphosphatidylglycerol (DPPG) with natural and dimethylsilyl polyamines are investigated first in the presence of NaCl in the subphase. Next, experiments are performed to study the competition between natural polyamines and dimethylsilyl analogues. The results obtained by surface pressure and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) with NaCl, are compared with those obtained with distilled water. A decrease of the DPPG mean molecular area is observed due to the local diminution of the Na + concentration close to the polar head group and the simultaneous onset of interactions between the amino group of natural polyamines and the polar head group of DPPG. The same effects occur with azhepsi, followed by an insertion of the hydrophobic dimethylsilyl group. Near the polar head groups DPPG, a substitution of the Na + by the amino groups of polyamines occurs. For the competition experiments, whereas a partial substitution is possible after putrescine and spermine adsorption, it is almost complete after spermine adsorption. Since the number of amino groups of azhepsi and spermine are the same, hydrophobic interactions due to the presence of dimethylsilyl group occur between azhepsi and the alkyl chains of DPPG. This favoured insertion of azhepsi provides a basis for understanding of the action of dimethylsilyl derivatives in the case of an antitumour strategy.

Design and Synthesis of a Novel Water-Soluble NMDA Receptor Antagonist with a 1,4,7,10-Tetraazacyclododecane Group

Polyamines, especially spermine, inhibit N-methyl-D-aspartate (NMDA) receptors as open channel blockers. Two types of water-soluble NMDA receptor antagonist, ACCn (1) and TGCn (2), with a 1,4,7,10-tetraazacyclododecane cyclic polyamine group, were synthesized and the effects of both compounds on NMDA receptors were studied using voltage-clamp recordings of recombinant NMDA receptors expressed in Xenopus oocytes. These compounds inhibited macroscopic currents in both NR1/NR2A and NR1/NR2B receptor subtypes in oocytes voltage-clamped at -70 mV. Inhibition by the compounds of NR1/NR2A receptors were more prominent than that of NR1/NR2B receptors. The inhibitory effects of ACCn (1) on both NMDA receptors were more potent than those of TGCn (2).

Studies of the Selective Removal of Microquantities of Platinum(IV) Ions from Model Chloride Solutions onto Ion Exchangers Containing Functional Tertiary Amine and Polyamine Groups

Since platinum is applied widely in industry, the recovery of noble metals from industrial wastes becomes an economic issue. Laboratory studies have been undertaken of the selective removal of microquantities of Pt(IV) ions from 0.1–6 M hydrochloric acid solutions onto ion exchangers containing functional tertiary amine groups (Amberlite IRA-67 and Amberlite IRA-93) or functional polyamine groups (Diaion CR 20). The recovery factor values [% R Pt(IV)] were determined for these ion exchangers as well as the sorption isotherms which depended on the kind of aqueous phase employed and the phase contact time. In addition, the weight and volume distribution coefficients, the number of theoretical plates as well as the working ion-exchange capacities were calculated from the Pt(IV) ion breakthrough curves. Due to their high ion-exchange capacities relative to Pt(IV) ions and their high resistance towards chemical agents, these ion exchangers may be applied both in platinum recovery technologies and in analysis o...

Convergent and Sequential Synthesis of Dendritic, Multivalent Complexing Agents

Two series of macrocyclic polyamine derivatives with various length of linkers were synthesized as dendritic ligands containing two, three, four, five or six terminal nitrilotriacetic acid (NTA) groups through convergent and sequential pathways. Tetrafluorophenyl esters were employed as activating reagents in the coupling step of assembling NTA groups to the cyclic polyamine head. A key step of the sequential synthesis is the use of the coupling reagent. 2-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) for the formation of amide bonds between the cyclic polyamine and pendant groups. Finally, two representative compounds were used to demonstrate the formation of stoichiometric protein assemblies.

Adsorption of Polyisobutenylsuccinimide Derivatives at a Solid−Hydrocarbon Interface

The adsorption of polymer dispersants of the polyisobutenylsuccinimide series has been studied at the solid/xylene interface. Carbon black was studied as a model solid. Adsorption isotherms were determined, the enthalpy of adsorption was measured by calorimetry, and the thickness of the adsorbed layer was obtained from small-angle neutron scattering. The paper emphasizes the structure−properties relationships with the help of a series of polyisobutenylsuccinimides having different polyamine groups and different polymer architectures, simple diblock (PIBSI) and comblike structure (polyPIBSI). The polyamine part ensured a strong adsorption on the solid surface, which increased in strength with the number of amine groups. In the same way, changing the diblock structure for a comblike one led to an enhanced affinity of the polymer for the solid surface. The adsorption was enthalpic but the Gibbs free energy of adsorption remained moderate because of a large entropy loss during adsorption. There was an enthalpy−entropy compensation phenomenon. Below a concentration of 70 mmol/m3, the polymers adsorbed as a 30 Å thick monolayer and the adsorption phenomenon was irreversible, due to the polymeric nature of the polar part. A drastic increase of adsorbed amount took place for higher concentrations. The formation of reverse hemimicelles was assumed as the origin of this phenomenon. The supplementary adsorption was reversible, showing that the polymer−polymer interactions were weaker than the polymer−surface interactions.

Analysis of pigeon intestinal mucin allergens using a novel dot blot assay

Many glycoproteins contain multiple glycosylation sites that can present multi-valent epitopes for antigenic recognition. Release of the oligosaccharides results in loss of avidity of antibody binding, which has been overcome by reforming clustered ligands, usually by reductive amination of free reducing oligosaccharides to poly-amine groups. We have adapted this approach to hydrazinolytic release of O-linked chains of mucin glycoproteins and ‘one-pot’ microscale coupling to poly- l-lysine (PLL). The conjugated PLL adheres to nitrocellulose membranes through washing procedures required for antibody or lectin overlay and detection. We show evidence for the applicability of this technique using lectin and antibody reactivity to the oligosaccharides of pigeon intestinal mucins, which have been implicated in the allergic disease pigeon fanciers’ lung.

ChemInform Abstract: Synthesis of Oligonucleotides Bearing Polyamine Groups for Recognition of DNA Sequences

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Oligonucleotides Bearing Polyamine Groups for Recognition of DNA Sequences

A 2-sperminoguanosine nucleotide has been synthesized and incorporated into oligonucleotides which showed increased duplex melting termperature.

Gas-phase basicities of polyamines

The gas-phase basicities of a group of multidentate polyamines have been determined by the bracketing method and range from 966 to 1021 kJ/mol. The compounds studied vary in the number and kind of basic sites, the number and orientation of carbon atoms, and the degree of flexibility. These important structural features were analyzed to understand the observed trends in basicity and semiempirical calculations were undertaken that support the experimental trends. The polyamines may find use as reference compounds for future gas-phase basicity measurements of larger, biologically active molecules such as peptides and proteins.

Modulation of DNA Triplex Stability Through Nucleobase Modifications

Spermine conjugation at4 N of 5-Me-dC in oligonucleotides (sp-ODNs) reduces the net negative charge and these as HG strands form triplexes with foremost stability at neutral pH (7.3), in contrast to unmodified ODNs which form stable triplexes at pH 5.5. The stability of sp-ODN triplexes is shown to arise kom improved association with duplex caused by electrostatic interaction of polycationic spermine sidechain with anionic phosphate backbone of DNA and N3 protonation is not a pre-requirement for triplexes constituted from sp- ODNs. The amplification of electrostatic component of interaction can be achieved by transformation of primary amino group of polyamines to corresponding guanidinium functions leading to improved binding and stabilization of DNA triplexes even at pH 7.0. %-Amino-dU ODNs are shown to be compatible as a central strand in formation of triplexes in which pyrimidine would be in the middle position of a triad.

Synthèse De Spermine Et De Spermidine Sélectivement Substituées Sur Les Fonctions Amines Secondaires

AbstractProtection of the primary amino group of various polyamines followed by alkylation or benzoylation at the secondary amino group and finally removal of the protecting group leads to the N‐methyl (23, Scheme 3), N‐benzoyl (11, Scheme 1) (ethylenetriamine, N‐benzoyl spermidine (22, Scheme 3), N, N′‐methyl (27, Scheme 4)‐ethyl (28, Scheme 4),‐propyl (16, Scheme 2) ‐benzoyl (15, Scheme 2) spermine.

The use of alkylene polyamines to isolate radulae. I. Relations between effectiveness and chemical structure.

To overcome the deficiencies of previously existing techniques to isolate radulae, a practical and rapid method was developed. It involves no mechanical action and effectively replaces all former techniques. The buccal mass, head or animal is boiled in 90-100% 1,3-propanediamine or other suitable polyamine. After a few minutes, tissues are selectively and completely dissolved. The radula, jaws and cuticular formations are left unusually clean, with natural color, with young teeth unaffected, and without shrinkage. The strong power of these amines to dissolve tissues, indicates that the method is suitable in other fields where the isolation of a harder formation from surrounding tissues is required by chemical means only. Useful properties are limited chiefly to a restricted group of low molecular weight alkylene polyamines belonging to the general formula NH2(CH2)nNH2, and to higher polyamines in which this structure is repeated through imino linkages and their hydroxy or hydroxyalkyl derivatives (by N- and N,N-substitution only). General requirements are straight hydrocarbon chains and highly polar positions for the NH2 and OH radicals.